The 'Full Moon' Secret level in Dungeon keeper 2 is the last secret level in the game. It requires no secret special to unlock it but is only made available to play when the date of the game is set to a day that the Moon is full in the sky.
The players objective here is to possess the only available salamander and destroy all the rival imps that try to claim your dungeon. If they succeed in taking over two of your rooms, then the mission will be lost. Also, if rival imps are still alive after the time limit has exceeded then the level is also failed. Destroying all the enemy imps wins the player the level.
To start this level, a moon will hover above the campaign selection screen, simply select the moon to begin it.